Magneto generator



1,626,367 Aprll 26, 1 THOMPSON MAGNETO GENERATOR Original Filed Feb. 15. 1919 4 Sheets-Sheet 1 INVENTOR 0/01 Fla/ 050 ATTORNEY Aprll 26, 1927. or THOMPSON MAGNETO GENERATOR Original Filed Feb. 15. 1919 4 Sheets-Sheet 2 0/02 Tia/7,050

ATTORNEY 0. THOMPSON MAGNETO GENERATOR Original Fi led Feb. 15. 1919 4 Sheets-Sheet 5 INVENTOR C Al ATTORNEY April 26,1927, 1,626,367

0. THOMPSON MAGNETO GENERATOR Original Filed Feb. 15. 1919 4 Sheets-Sheet 4 INVENTOR Hp.- 0/0/ 7/70/2050 k w) BY 6 W6% 2 m Q x ATTORNEY Patented Apr. 26 192K esser er Fl.

0L0 THOMPEvOlil, OF NEW" YGRK, N. Y., ASSIGNOE, BY DIESNE AFSIGIiTllEENTS, TU SKELET- DfiBI --BEIFHLEHEM ELECTRICAL COMPANY, OF HEW'ARK, NEW JERSEY, A (JOB.-

PORATION 01 NEW IVLAGNETO GENERATGE.

Application filed February 15, 1919, Serial No. $77,229.

'lhis invention relates generally to magnetos with -1Otating armatures used for igniting the charge in internal combustion en gines, and it more particularly appertains to that type of magnetos which are equipped with primary and secondary windings.

Prin'iarily, the invention has for its object to produce an improved magneto wherein the primary and secondary wmdings shall be separately mounted, so that they may be insulaied from each other at all times and under all conditions, thereby precluding short-circuits and removing a prolific source of trouble in the running of the engine.

A secondary object is the production of a magneto of the type aforesaid having separate cores for the said windings located in the same magnetic field and subject to the generating action of the rotor, whereby the capacity of each core to carry an amplified amount of conductive wires is enhanced, while the respective windings are enabled to be placed in inductive relation to each other without increasing the size of the apparatus.

A third object is to provide a high tension magneto in which the secondary winding is located exteriorly with relation to the primary winding on the armature, so that the windings may be applied to their respective cores with greater accuracy and celerity, and either one of the latter can be dismantled independently of the other.

A fourth object is the provision of a structure comprising a powerful primary winding on a rotatable armature cooperating with an equally efiicient secondary winding held stationary with relation thereto, both.

windings being subject to the same magnetic flux and so disposed within the frame of the device that either one of them will utilize a space therein heretofore left unoccupied.

A fifth object is to devise a construction of the character described including a core for the fixed secondary winding extending at substantially right angles to the axis of rotation of the armature that carries the primary winding and arranged centrally be- Renewed June 18, 1823.

to repair or renovate; adaptability to production by machine operation; practical elimination of manual fitting; and general dependability.

Other objects and advantages of the invention will become apparent as the specification proceeds.

/Vith the aforesaid objects in view, the invention consists of the novel combinations and arrangements of parts hereinafter described in their preferred embodiments, pointed out in the subjoined claims, and illusrated on the annexed drawings, wherein like parts are designated by the same reference characters throughout the several views.

In the said drawings,

Figure I is a longitudinal vertical section, showing a practical embodiment of the invention;

Fig. II is an end view of a current interrupter or contact-breaker included in the device;

Fig. III is an end view, looking from the left-hand side of Fig. I;

Fig. IV is a central vertical section;

Fig. V is a sectional plan, the section being taken on line VV of Fig. I, looking downward Y Fig. V1 is a similar section, on line VI-VI of Fig. I, again looking in a downward direction;

Fig. VII is a diagram illustrating the relative positions of the primary and secondary windings; and

- Fig. VIII is a similar view, representing the two windings connected up in series.

Described in general terms, the invention tit) may be said to include a two-fold magnetic field constituted by permanent magnets ot the straight bar species placed in parallelism and united transversely at one end by a base upon which the bars stand and by a bonnet overlying them at the opposite extremity. The centre of the field is occupied by a fixed core evtending from,the bonnet to one of a pair oi oppositely disposed pole-pieces, the other of which is attached to the base. Between the pole-pieces revolves an armature carrying but one winding to wit, the prirary. The fixed central core is surrounded by a secondary winding placed in inductive relation to the primary winding on the armature. Both windings consequently are located in the same magnetic tield and subject to the generating eti'ect ot the armature tho they are separated from each other. Located in an axial direction with respect to the armature is the mechanism for interrupting the tiow of current thru the pri mary circuit. Adjacent to this mechanism is a condenser which controls the fluctuations oi the interrupted current and is situated also in the plane of the armature. Disposed to one side of the latter named parts and approximately in alignment with the secondary winding is a device adapted to convey the induced current therefrom and distribute it to the various spark plugs of the engine. The elements respectively associated with the primary and secondary circuits can be included therein either in separate groups or in serial relation.

The advantages of the invention as here outlined are best realized when all of its features and instrumentalities are combined in the one and same structure, but, useful devices may be produced embodying less than the whole.

It will be obvious to those skilled in the art to which the invention appertains, upon becoming conversant with the details thereof, that the same may be incorporated in several different constructions. The accompanying drawings, therefore, are submitted only as showing the preferred exemplification ot' the invention.

The improved form of the device herein disclosed rests as a whole upon a base A, which may be rectangular as shown, or of any other convenient shape and dimensions. This base, preferably, is formed with lips or upwaidly-projecting sides A designed to retain in place a pair of bar magnets, to which special reference will be made here inaitcr.

Fastened to the said base on the rightehand side thereof, is a head B of non-magnetic metal, which in the present embodiment of the invention constitutes the driven end of the magneto. Within this head an oilchamber B is formed, to which leads an C leading to the same, which is fed by means t an oil-cup C provided with a lid C From the lower halt of the head C projects outwardly a housing D, designed to enclose the aforementioned contact-breaker or electric current interrupted. This part of the device. it is understood, consists of mechanical means adapted to cause a sudden interruption in the current flowing through the primary winding of the magneto, and simultaneously to give rise to a high tension current in the secondary winding, which is expended as a spark at the ignition point.

Against the housing D is held a condenser casing E, of which E is the outer head. it resilient arm Ff holds the outer head against the casing. and the latter to the housing. is represented in Figs. I and ill, the lower end of this arm is attached to a stud l5". screwing into the bottom edge of the head C. [an adjusting lever E" takes over the casing E, and is employed to vary the relative positions of contacting elements of the interrupter so as to predetermine the time at which they should be separated. Similarly to the interrupter, the condenser is fitted to the primary circuit ot the magneto. and serves to absorbthe reverse current at the point of interruption, which it subsequently returns to the primary winding when the contact is reestablished.

i distributor plate F is held against the head C, above the upper half of the housing A number of sockets F are provided on this plate, each titted with a plug F Preferably, the magneto is furnished with the usual form of 5 -section armature, comprising heads G G, held together by rivets or studs G with a laminated centre section G therebetween, the latter being composed for instance, of soft iron laminae adapted to reduce the internal re ista'nce encountered by the lines of magnetic force passing through the armature. lhe before-mentioned primary winding, herein denoted by the reference character G", is carried by the said arn'iature heads G, over the said centre section G According to the present invention. the primary winding is composed only of relatively heavy conductive wires, which are thoroughly insulated from one another, as well as from the exterior.

At the opposite extremities of the armature are two shafts respectively designated eases? by H and H the former being at the driven end, and the latter at the othc" end. An enlargement H or flange, is nrovided at the inner end of the shaft H ant also a separate flange ll" at the inner end of the shaft ll. lioth of the parts H and H are held to the heads G, as by screws H.

Ball-hearings 1 are provided to support the shaft H, within the lower part of the head it. Similar hearings I are supporting the shaft H in the corresponding portion of the head 1).

The said shaft H carries a pinion J. The latter is driven by key pins J, projecting outwardly from the flange or enlargement ll A nut J engaging an external screwthread on the shaft H holds the pinion J against the said flange or enlargement.

A gear-wheel K is in meshing engagement with the pinion J, which is located under the same. This gear-Wheel is mounted upon a hollow shaft K journalled in a sleeve K The latter-named element is carried by the boss C previously herein mentioned as pertaining to the head C.

The interrupter or contact-breaker includes an actuating cam L, made of fiber and having a taper fit in the outer end of the shaft H substantially as shown. Adjacent to this cam is a lever L pivoted as at L", on the inner face of the condenser casing E. A roller L is carried by the lever L in contact with the cam L. A contact-piece L, such as a button, screw or the like, is also carried by the lever, and opposite the samev is a corresponding contact-piece L", adjustably mounted in an insulated block L projecting from the inner head of the condenser casing. .The lever L is held to its pivot L b the free end of an arm L, which is secure to :1. lug L, on the said inner head of the condenser. A fiat spring L is further anchored to an angular oflsetportion L of the same lever. The other end of the spring L is attached to a log L, also projecting from the said inner head. Another spring L, preferably of U-shaped formation, affords a. ground connection for the primary circuit. This spring has its free end in contact with the outer end of the shaft H with which-one terminal of the primary winding is connected. as by soldering it to armature G. A third lug L, to which the other end of the spring L is secured, extends from the condenser casing E. The cam L is drawn into the open outer end of the shaft H by a bolt L. A nut L", engaged by the bolt L, is provided at the inner end of this shaft, from Which'it is so aratedby a suit able insulation, as L". To the nut L is connected the other terminal of the windin 3 Within the casing E is placed the con primary denser proper, composed of internal layers M. Connected with one side of the condenser is a resilient arm M, while the other side thereof is grounded through casing l). A holder M is attached to the arm, and

made to carry a carbon hrnsh M in con- I tact with the head of the bolt L. The arm M is also suitably connected electrically to the block L.

A non-conductive arm N is held to the gear-wheel K, at or near the hub thereof, as by screws N. This arm has a sleeve N also of non-conductive material, but carries a conductive finger N held in position by a screw l The latter is formed with a hol low head in which is lodged a coil spring N urging a plunger N against the head of acontact terminal N The plunger is carried by a sleeve N A holder N is formed with the outer end of the arm N, within which is fitted a conductive sleeve N constituting an extension of the conductive finger N "Within the sleeve N is received a carbon brush N Contact blocks 0 are imbedded in the plate F of the distributor, at the inner side thereof. From these blocks extend posts 0 onto which the plugs F are screwed. ()n the same posts are also collars 0 against which wires leading to the spark plugs are forced by the before mentioned plugs F The carbon brush N wipes over the blocks 0 as the gear K is being rotated.

Permanent, straight-bar magnets P are. made to stand with their lower ends on the base A within the lips A Overlying the upper ends of these magnets is a bonnet P, set in opposed relation .to the base A. and fitted between the top portions of the heads B and C. Lips P on the bonnet P retain the magnets in position. The magnets P, it is understood, produce the field of force from which the initial or primary current in the magneto is derived. Coacting with the lips A and P to retain the bars P in position. are provided other lips B and O onthe heads B and C respectively.

. Extending ina groove transversely across the bonnet P are laminae Q, held therein by a stud Q}, upset endwise.

the base A, and are included in the lower pole-pieces standing in operative relation to the laminae G to which particular refer once was previously made The laminae Q Other laminae Q are carried 1n a groove transversely of core are vertically-disposed segments Q, risiug from a base Q]. integral therewith. These several parts Q, Q, and Q are secured together by headed 'studs Q The base Q is separated from the lamina) Q through the interposition of non-magnctic pieces Q.

The base A with the embedded laminae Q constitutes a lower pole structure of one polarity and the pole piece Q}, core extension Q and bonnet P with embedded laminae Q. constitute an upper pole structure of the opposite polarity. These two pole structures taken with the permanent magnets P constitute the stationary field structure of the generator.

Surrounding the core Q is a secondary winding Q consisting of numerous convolutions of fine wire. This winding is insulated from the core Q7 and its lateral segments Q, by a tube Q passing through it. An outer, cylindrical wall Q also surrounds the secondary winding. Both the tube Q and outer wall Q may be formed integral with the base plate Q upon which they stand. The insulating tube Q, is further engaged at its upper end by a centrally apertured cover Q, adapted to be screwed exteriorly thereon and forced down upon the upper edge of the cylindrical wall Q, with packing Q, intervening therebetween. The said tube Q cylindrical wall Q integral bottom Q and cover Q, constitute together a closed receptacle, providing a hermetic container completely enclosing the secondary winding QB". By referring to Figs. I and IV, it will be seen that a suliicient space is left between the winding Q, and the cylindrical wall Q, to permit introduction therein of some compound adapted to envelop the winding and insure its thoro insulation. As illustrated 'in Fig. I, a screw Q is connected with the lower end of the secondary winding Q, and constitutes a ground connection therefor in the base plate Q The upper end of this winding terminates in a connection Q," coupled with the contact button N whereby the induced current flowing thru the winding is conveyed to the distributor. It will be noted that the container for the secondary winding can be readily removed with it as a whole from its core and this can be done independently of the armature and primary winding.

VllGS R lead from the plugs or binding posts of the distributor to spark gaps S, which are in turn connected to ground, as is also one end of the secondary winding Q. In the wiring diagram of Fig. VII the winding Q, is connected to ground directly while in that of Fig. VIII such connection is made indirectly through the primary winding G Other conductors (indicated at T in Figs. VII and VIII, but made up of above-described structural parts actually) connect the interrupter and the condenser in series. One of the conductors T may form part of a ground connection. In the diagram Fig. VII, the current tension at the spark gap is that derived from the secondary winding alone. IVhereas, in the layout disclosed by Fig. VIII the current pressure is cumulative, in the sense that the two windings are connected up in series with the spark gaps, by the wires U and U Altho these two diagrammatic representations indicate that only one secondary coil is used, it is quite conceivable that the same can be divided into a plurality of similar coils, either connected or separate from one another, or that different leads may be taken out atvarious points from a single coil.

It will, of course, be understood that in the operation of my generator the generating etlect on the secondary winding incident to the continued rotation of the rotor after the interruption of the primary circuit, serves to augment and sustain the current flowing in the secondary circuit in the same manner as in the prior direct high tension magneto generators in which the primary and secondary coils are wound on the same core.

Among the several advantages obtained by the construction hereinabove described the following may be noted :Due to the arrangement of the primary and secondary windings on separate mounts, both of them receive the full benefit of the constant flow of the lines of force emitted by the permanent magnets, the flux being uninterrupted and continuously following its natural course along the permanent magnet bars and the coil carrying cores enclosed thereby. The secondary winding, being stationary with respect to the rotatable armature that carries the primary winding, is in the most favorable position for purposes of induction, and both windings are best situated to perform their respective functions. Inasmuch as the windings are coiled around separate cores, a larger quantity of the conductive wires can be used for either winding, and a magneto of given size thus wound will produce more current than can be obtained in devices where both windings are on the one armature. This method of winding, it will be observed, does not operate to enlarge or complicate the construction, since the increased amount of conductor is lodged in space previously unoccupied.

To refer particularly to the secondary winding, the wire surrounding the core thereof may be machine wound, thereby mini mizing cost of production and enabling the winding to be applied or removed without disturbing the armature winding. A better opportunit to insulate the working parts efliciently rom one another is also afiorded.

Besides, the secondary winding being separate and stationary, is especially well adapted to be isolated within a casing of its own forming therewith a self-contained struc:

ture. By simply separating the bonnet P from the core Q, the coil Q can be removed from the core Q without dismounting the rotor.

While a certain preferred embodiment of this device has been shown and described, it will be understood that changes in the form, arrangements, proportions, sizes and details thereof may be made, without departing from the scope of the invention as defined by the appended claims.

Having described my invention what I desire to secure by Letters Patent and claim, 1s:-

1. A device of the type specified including means for producing a permanent magnetic field, a single winding therein de signed to generate an electric current, a separate winding therein for deriving an induced current from the first winding, and means adapted to rotate one of said windings while the other remains stationary.

2. A device ofthe type specified including means for producing a permanent magnetic field, a rotatable armature, a primary winding mounted alone thereon, a stationary core in inductive relation to said armature, and a single secondary winding carried by said core.

3. A device of the type specified including an armature carying a single primary winding, a relatively fixed core supporting a single secondary winding in inductive re lation to said primary, and means for rotating said armature with res ect to said core in a permanent magnetic held.

4. A device of the type specified includ ing means for producing a permanent magnetic fie'ld' separate cores contained therein, single rnna and secondary windings mountain in active relation to each other upon said cores and means for rotating one of the cores w 'ile the other one is main- .tained in a fixed position.

5. A device of the type specified including permanent bar magnets isposed in parallelism and coupled together at their opposite extremities, a rotatable armature and a fixed core occupying a central position intermediate of said bar magnets, and windings of the primary and secondary types respectively carried by said armature and said core in inductive relation to each other.

6. A devic'e of the type specified including parallel bars permanently magnetized, transverse connections for the ends thereof, an armature having a primary w nding rotatable in proximity to one of said connections, a stationary core with a secondary winding extending from the opposite connection towards said armature in Inductive relation thereto, and opposed pole-pieces for the latter on the ad acent connection and upon said core.

7. A device of the type specified including arotatable armature with a primary winding thereon, a fixed core having a secondary winding disposed at substantially right angles to the axis of rotation of said armature, permanent bar magnets extending parallel to the longitudinal centre oi said core, and bridging pieces connecting up the opposite extremities of said bar magnets.

'8. A device of the type specified including means for producing a permanent magnetic field, a rotatable armature having a single primary winding, an interrupter in the plane of said armature connected up in the circuit of said primary winding, a fixed core with a singlesecondary winding separately mounted thereon in inductive relation to the primary winding, a distributor operatively coupled up with the circuit of said secondary winding approximately in theplane thereof, and an igniter contained in the latter named circuit so as to be con trolled by said distributor.

9. A device of the type specified includ ing a rotatable armature with a primary winding, an interrupter actuated "from said armature within the circuit of said primary winding, a condenser positioned in the same circuit in axial alignment with both the armature and said interrupter, a stationary core having a secondary winding located exteriorly from the armature and its winding in inductive relation thereto, an igniter contained in the circuit of said secondary winding, and a distributor driven from the armature controlling the induced current from the last named winding to said igniter.

10. A device of the character described including means for producing a permanent magnetic "field, a'rotatable armature with a primary winding alone thereon, a fixed core carrying a single-secondary winding bes de said armature, said armature and core being disposed in said field, an interrupter in the circuit of said primary inding driven by the armature, a distributor actuated by the latter opposite said secondary winding so as to control induced current therefrom, and an i iter in the circuit of the last named winding receiving the current from said distributor in timed relation to said interrupter.

11. A device of the character described including a permanent ma netic field comprising substantially para lel bar magnets, an armature with a primary winding alone thereon rotatable between the latter, pole pieces disposed on opposite sides of said armature, a core extending from one of said pole-pieces, a single secondary winding on said core,'and connecting members coupling sa1d bar magnets together and with ill) said core so as to complete the magnetic circuit.

12. A device of the character described ineluding a permanent magnetic field comprising bar magnets located in substantial parallelism with one another. connections join ing the opposite poles thereof, a core extending inwardly from one of said connections intermediate of said magnets, a single secondary Winding around said core, polepieces disposed opposite the inner end of the core and the other one of the connections, and an armature with a primary Winding alone thereon arranged to rotate hetwecn said pole-pieces.

- OLOF 'll-IOMPSON. 

